These findings, which could help lead to the development of diagnostic tools and therapies for this baffling condition, appear in the March 2003 issue of The Journal of Clinical Investigation.
Also known as toxemia, preeclampsia occurs in an estimated 5 percent of all pregnancies, affecting approximately 200,000 women in the U.S. each year. The condition typically develops after the 20th week of pregnancy and in mild cases, is characterized by high blood pressure, edema, and protein in the urine. In severe cases, the condition can rapidly develop into eclampsia, in which the mother suffers serious and potentially fatal seizures.
"Currently, there is no treatment for this condition," says the study's lead author S. Ananth Karumanchi, M.D., of the Renal Division at BIDMC and Instructor of Medicine at Harvard Medical School. "The only management we can offer patients is to deliver the baby and the placenta, which can result in the infant being born prematurely." As a result, preeclampsia is one of the leading causes of maternal and infant mortality in developing countries.
In a normal pregnancy, the developing fetus signals the mother's body to widen blood vessels to the placenta, which supplies oxygen and nutrients to the fetus. But, for unknown reasons, in women with preeclampsia the blood vessels grow narrower, impeding the flow of blood and oxygen. The diminished oxygen levels apparently set in motion a rapid progression of potentially fatal complications involving the mother's liver, kidneys, lungs, blood and nervous system.
Scientists have long speculated that the placenta was releasing some unknown factor that was triggering this abnormal course of events. In order to identify this factor, Karumanchi and his colleagues first
Contact: Bonnie Prescott
Beth Israel Deaconess Medical Center